From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F7FFC49ED7 for ; Fri, 20 Sep 2019 14:32:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E11DF207E0 for ; Fri, 20 Sep 2019 14:32:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390113AbfITOcF (ORCPT ); Fri, 20 Sep 2019 10:32:05 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36690 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388334AbfITOZN (ORCPT ); Fri, 20 Sep 2019 10:25:13 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqP-0004y7-Kz; Fri, 20 Sep 2019 15:25:09 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqF-0007vP-Sc; Fri, 20 Sep 2019 15:24:59 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Dan Carpenter" , "Mauro Carvalho Chehab" , "Hans Verkuil" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 085/132] media: omap_vout: potential buffer overflow in vidioc_dqbuf() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit dd6e2a981bfe83aa4a493143fd8cf1edcda6c091 upstream. The "b->index" is a u32 the comes from the user in the ioctl. It hasn't been checked. We aren't supposed to use it but we're instead supposed to use the value that gets written to it when we call videobuf_dqbuf(). The videobuf_dqbuf() first memsets it to zero and then re-initializes it inside the videobuf_status() function. It's this final value which we want. Hans Verkuil pointed out that we need to check the return from videobuf_dqbuf(). I ended up doing a little cleanup related to that as well. Fixes: 72915e851da9 ("[media] V4L2: OMAP: VOUT: dma map and unmap v4l2 buffers in qbuf and dqbuf") Signed-off-by: Dan Carpenter Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Ben Hutchings --- drivers/media/platform/omap/omap_vout.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) --- a/drivers/media/platform/omap/omap_vout.c +++ b/drivers/media/platform/omap/omap_vout.c @@ -1596,23 +1596,20 @@ static int vidioc_dqbuf(struct file *fil unsigned long size; struct videobuf_buffer *vb; - vb = q->bufs[b->index]; - if (!vout->streaming) return -EINVAL; - if (file->f_flags & O_NONBLOCK) - /* Call videobuf_dqbuf for non blocking mode */ - ret = videobuf_dqbuf(q, (struct v4l2_buffer *)b, 1); - else - /* Call videobuf_dqbuf for blocking mode */ - ret = videobuf_dqbuf(q, (struct v4l2_buffer *)b, 0); + ret = videobuf_dqbuf(q, b, !!(file->f_flags & O_NONBLOCK)); + if (ret) + return ret; + + vb = q->bufs[b->index]; addr = (unsigned long) vout->buf_phy_addr[vb->i]; size = (unsigned long) vb->size; dma_unmap_single(vout->vid_dev->v4l2_dev.dev, addr, size, DMA_TO_DEVICE); - return ret; + return 0; } static int vidioc_streamon(struct file *file, void *fh, enum v4l2_buf_type i)